Self-laying endless track type vehicles typically utilize an endless track assembly joined together by interconnected link assemblies. The link assemblies include overlapping link members which form a pair of continuous rails which track rollers of the vehicle roll along. The endless loop track is driven by a powered sprocket wheel at one end of the vehicle, and an idler wheel at the opposite end of the vehicle reverses the direction of travel of the endless loop track.
Conventionally, one or more carrier rollers guide and support the upper portion of the track between the idler wheel and the sprocket wheel. The carrier rollers generally rotate as the link rails pass across the rim portions of the rollers. Rotation of the carrier rollers is dependent on friction generated between the rail surfaces and the roller rim surfaces. Considerable noise is produced from the engagement of the roller rims with the rails and wear is a natural result of continuous contact between those metal components. If for various reasons the carrier rollers do not rotate properly, the wear rate between the rails and the roller rims is accelerated. Rapid wear of the roller rims necessitates replacement of the roller rims or, in some cases, the entire carrier roller. Continued wear on the rails would ultimately require repair or replacement of the track link members.
One type of track roller having a replaceable tread portion is disclosed in U.S. Pat. No. 3,871,719, issued on Mar. 18, 1975 to R. L. Boggs. The replaceable tread portions of this roller are formed of a metallic strip in the form of a plurality of convolutions. Preferably, the convolutions are defined by a helix with each convolution in the helix being in abutment with the adjacent convolution. The treads are held in place between a pair of flanges and can be replaced by removing one or more of the flanges. Although this type of roller assembly would appear to function satisfactorily, it would be subject to the wear and noise problems outlined above.
Another type of track roller having a resilient mounted tread is disclosed in U.S. Pat. No. 3,910,128, issued on Oct. 7, 1975 to R. L. Boggs et al. The tread portion of this roller includes an inner resilient collar and an outer metallic ring. The tread portions are held between a pair of flanges and the flanges are secured in place by threaded retaining means. The use of the inner resilient collar is intended to extend the useful life of the outer metallic ring. This particular arrangement would appear to function satisfactorily for its intended purpose. However, it would seem to be susceptible to some of the wear and noise problems previously mentioned.
Still another type of track supporting roller having a resilient rim is disclosed in U.S. Pat. No. 3,996,810, issued on Dec. 14, 1976 to E. R. Groff. The rim, or tread portion, of the roller is constructed from a plurality of separate resilient pads. These pads have a generally rectangular shape and include an aperture formed in each pad. The plurality of pads are banded together into an annular configuration by a steel band disposed internally though the apertures. This roller construction is intended to reduce the noise generated between the running engagement of the endless track chain and the roller, and would appear to operate satisfactorily for that purpose. However, the assembly contains a considerable number of parts and requires time and effort to assemble the parts together.
The present invention is directed to overcoming one or more of the problems as set forth above.